Continuous slab-heating furnace



June 12, 1928. 1,673,771

F. W. MANKER CONTINU'US SLAB HEATING FURNACE Filed July 15, 1925 4 sheets-sheet l' .lune 12, 1928. 1,673,771

F. W. MANKER CONTINUOUS SLAB HEATING FURNACE Filed July l5, 1925 4 Sheets-Sheet 3- 5ft/wanton /7 m MA N KE FL t* his @Wou/10% www Patented June 12, 1928.

Nitro 4STATES l1,673,771 Ica.

FORRESI' WILLIAM MANKER, OF JACKSON HEIGHTS, NEW YORK, ASSIGNR T0 SUR- FACE COMBUSTION COMPANY, 0F NEW YORK, N. Y., A CORPORATIN OF NE'W YBK CONTINUOUS SLAB-HEATIN G FURNACE.

Application filed July 15, 1925. Serial No. 43,699.

This invention relates to furnaces and more particularly to furnaces for continuously heating slabs or pairs or the like.

It is an object of the invention to provide a slab heating furnace yin which the slabs or other work to be heated may be efficiently and uniformly heated from below as well as labove while they are being moved through the heating chamber.

Another object is to provide a slab heating furnace in which the-tracks onwhich.

the slabs are supported shall be elevated from the floor of the heating chamber Whereby to form channels or conduits along which the hot gases may flow beneath slabs to heat the same.

A still further object is to provide a slab heating furnace having longitudinally extending channels along which the hot gases may liow and to provide means for covering over certain portions of the side channels, more particularly in front of the side doors through which the slabs may be removed from the furnace, and to provide means for intercepting'the flow ofwgases in the side channels before they enter the covered over channels.

An additional object is to provide a slab heating furnace in which-the slab supporting tracks shall have a gradient extending up-` wardly from the charging to the discharging end of the heating chamber whereby to keep the slabs from falling over on their sides toward the discharging end of the chamber as they are moved therethrough.

Another Objectis to provide a slab heating furnace of such construction that the burning gases shall passthrough the heating chamber continuously in one direction and out of the same through the port-s in the floor of the chamber beyond the last side door so that any air entering the heating chamber by way of the doors may be prevented from exercising any pronounced oxidizing ell'ect on the slabs while they are being heated.

A still further object is to .provide a slab heating furnace wherein the flow of gases from the heating chamber may be regulated and wherein the air which supports secondary combustion of the combustible gases may be readily regulated.

Another object is to provide a furnace construction wherein a recuperator for preheating the air to be used for supporting secondary combustion shall be located below the heating chamber in such manner that the products of combustion may pass directly from said chamber through the recuperator `and to provide a collecting chamber for the heated air between the floor of the heating chamber and the top of the recuperator.

The above and other objects of the inven tion, with their attendant advantages will more fully appear from the detailed description taken in connection with the accompanying drawings whichv form a part of this specification.

Referring to the drawings:

Figure 1 is a longitudinal, vertical section through the improved slab heating furnace. parts being broken away to more clearly i1 lustratc the construction;

Fig. 2 is a vertical cross-section taken on line 2-2 of F ig. 'l and illustrating the relation of the combustion chamber to the heating chamber and to the air and gas passages and also showing certain features of construction within the heating chamber; Fig. 3 is a vertical cross-section taken on line 3-3 of Fig. l and illustrating the construction of the recuperator and certa-in features yof construction Within the heating chamber; and

Fig. 4t is a horizontal crosssection taken on line --fl of Fig. l parts being broken away to more clearly show certain features of construct-ion.

In the drawings, l0 indicates the gas producers of which two are shown arranged side by side along one/side of a slab heating chamber ll into which they discharge their gases by way of ports or passages l2 and combustion chamber la opening into the slab heating chamber.

The air for supporting secondary combustion of the producer gases enters the combustion chamber through upright ports 16 in the partition wall or baffle 18 which is in effect a part of the side wall of the heating chamber. These ports are in communication with an airl chamber 20 formed at the top of a recuperator 22, suitable passages 23 connecting the air chamber with said ports. Fresh air is admitted to the Iecuperator through suitable passages 24 extending therebeneath and heated to a high temperature vas it circulates through the recuperator,

which latter is heated by the products of combustion flowing from the slab heating chamber as will presently be explained. The recuperator is preferably ot tile construction as illustrated in Figs. 1 and 3 and the air is heated by passing around the tiles in grooves or channels provided therebetween, the heated air collecting in the air chamber 20.

The partition or battle wall 1S is preferA ably provided with a. transversely extending passage 25 which is in eii'ect a distributing manifold `for the air coming from the hot-air collecting chamber 20. Y

The burning gases from the combustion chamber after traveling the length ot' the heating chamber, pass out of the saine by Way of outlet ports 2G in the Hoor thereof, the ports `being located at the far vend of the chamber (Figs. 1 and 4f).` These ports open on an upright passage 28 (Fig,'-l) which extends in front ot the recuperator. The products ot' combustion after passing through the recuperator enter a passage 29 at the far end thereof from whence tlieypass by suitable passage et() (Fig. l) to the stack, not shown.,

The effective size ot the outlet ports QG may be regulated by tiles S0 ivliicli rest on the Hoor of the heating chamber and which are adapted to be moved over the ports by a suitable tool inserted through the inspection portsl extending through the end wall ot' the furnace. ly varying thc'size of the outlet ports 2G the rate ot' flow of the burning gases through the heating chamber may be readily regulated and the circulation ot the saine around the Work etlectually controlled.

The etective size of the air ports 16 may also'be varied by shifting thel tiles 33 resting on top ot' the partition or battle 18, access being had to the tiles through 'inspection ports 32 in the adjacent side Wall of thc furnace. 'By thus regulating the amount ot' air which is to be mixed With the combustible gases coming from the producer, the character and temperature of the llame may be readily controlled. ln other words, the Haine can be readily controlled so as to be a reducing flame or oxidizing flame at will. Ordinarily the admission ot' air would be such that a reducing llame is obtained in order to prevent the torniation of scale on the slabs or other work being heated.'

rlhe slabs to be heated are generally indicated at X and are adapted to be snpported on a pair of tracks 38 which rests on piers 3G mounted in the central portion of the heating chamber in lspaced relation to each other and spaced 'from the side Walls of the heating chamber, tlrus forming a central and side channels in .Whichthe burning gases may How .toward the far end of the furnace as 4Will presently appear. The slabs slide on the tracks 38 as. they are. moved through .the heating chamber from one end to the other thereof, the slabsibeng fed to in height troni the charging to the discharging end of the heating chamber whereby a gradient'. is produced. lily providing 4a gradient the slabs are more readily maintained in a sloging position or at ait angle to the vertical and consequently there is less tendency tor thenrto talhover forwardly on their sides as they are pushed through lthe chamber.

The burning gases coming from the coin,- biistion chamber pass down the length o't the heating chamber., being drawn toward the far end thereof by the draft at the outlet ports 26. Sonie ot the burning i gases find their way into ,the central. and side channels 54 and 56 respectively 'formed by the piers 36, and tloiv toward the far cud ot the heating chamber. '.lhe burning gases will also circulate between the slabs4 inasmuch as there will usually be some space between them due either to burs or projec-` tions in their faces or because they are loosely stacked. lt will, therefore, be appreciated that the burning gases circulate not onlyover the slabs but also below and between them with the result that Athey are uniformly heated throughout. The piers are provided opposite the combustion chamber with lateral ports 52 through 'which the hot gases may circulate from one 4channel to another and more particularly from Side channels 56 into the central channel 54 for reasons that will presently appear.

Extending along one side of the heatingl chamber are a plurality oi. doors 58 through which the heated slabs may be taken out of the furnace the doors being arranged on a level with the tracks 38 onthe tops of the slab supporting piers. Arranged'. in each of the side channels is a transversely cxtending wall'tltl xwhich terms a barrier to the .tree tlovv of gases in the side channels. llacli side channel covered over by a. slab (i2 which extends from the barrier 60 a short distance beyond the last of the side doors. The covering slab may be one ycontinuous llll iet

piece or a plurality of pieces Aas indicated in y the drawings. While the barrier` 60 intercepts the free flow ot gases 1n the -side channels, .means are, however, provided lwhereby the hot gases from: the cent-rali' channel may ii-oiv into. the closed over lier,

channels through lateral port's 'Gi provided i in the piers beyond the barrier. t v

By covering over the side channel in front. ot theside doorsfthe flames, fromthe Levavri burning gases are prevented 'from passing through the doors when the latter are opened for the removal of the slabs. In addition to the side doors 58 there is provided an end door 66 through which the slabs may be removed it desired.

lnasnuch as the slabs to be heated are supported on elevated tracks rising from the Hoor of the heating` chamber. some of the flames or burning ,frases which enter the heatingy chamber from the side thereof will first be deflected downwardly by-the curved root ot' the heating chamber into that side channel farthest removed lfrom the bai ile 18 and under the slabs resting on the tracks or piers, the lateral passages or ports 52 in the piers., however, perniittii'igr the flames or hot gases to circulate freely bcneatli the slabs. The draft created by the stack makes itself felt at the portsQt in the far end of the heating chamber and consequently the hot gases Will travel along: the channels toward thes'e ports and out through the saine. By reason ot the tactthat harriei's G0 are provided in side channels. an eddying' ell'ect is set up iii the side channels opposite the combustion chamber with the result that the ends of the slabs projecting over the side channels will become thoroiighly heated by 'the time,l they have, reached the side doors 58. Furthermore. inasmuch asv the hot gases in the central channel are permitted to' flow into the covered-over portions of the side channelsthe cover tiles 62 or slabs are thoroughly heated from belaw and thus. While they prevent the hot-#gases in the side channel from flowing through the doors when the latter open, they ,assist inkeepinc' the ends of the slabs hot by radiation of their heat.

l/Vhile both side channels opposite theside doors have heen shown as covered over with tiles. it is Within the spirit of the invention to dispense with that cover tile and barrier farthest removed from the side doors 58, for the obvious reason that only one side of the heating' chamber is provided with side doors through which it is desired to prevent the flow of hot gases.

lt Will be noted that the hot gases flow continuously toward the far end ot the heatingy chamber. By thus confining the burning gases to a one direction movement before passing out of the heatingr cbainl'jer, any air which may leak in through the doors 58 is carried away trom the vvork toward the outlet ports 2G without having' had an opportunity of passing to the front ot the chamber and Without havin; q siifiicient time, to exercise anv material oxidizinpy ell'ect on the heated slabs.

Furthermore, by providirj for the control of the heated air which entersthe combustion chamber, the Haines may be readily maintained a reducing Haine so that any aii'.which enters through the side doors 58 or through the end door 66 will combine with the burning gases rather than exerelsing` an oxidizing effect on the slabs.

'lhe recuperator is located below the .door of the heating chamber to provide as direct a passage as possible for hot products of combustion as they pass on their Way to the stack. llurthermore, this construction enables a hot-air collecting chamber to be provided directly below the heated floor of the heating chamber whereby the air .will he further heated before passing on its Way to the. combustion chamber.

That is clainicd'is:

l. ln a continuous heating furnace open ing into one side of the heatingr chamber, thc combina tion of elevated work-supportingg piers extending` longitudinally of tlie'hea-ting chamber in spaced relation to each other and the chamber side walls to torni opento'p channels across which the work to be heated is/disposed for' l'ieating from below and above, means establishing transverse communication between 'the channels for a.

limited portion ot their length, and means for delivering a stream ot hot from an openingl 1n the chamber side Wall in a direction above and across the communica-- tion portion of said channels in a manner to permit said gases to flow downwardly along the chambcifwall opposite said openings and transversely through the communicating portions of said channels.

2. ln a continuous heating furnace havingits combustion chamber at one side ot' the heating chamber and havingdoors along la side wall' thereof, the combination ot'elerated piers extending longitudinally of the heating chamber in' spaced relation to each other and to the side walls of the saine to forni channels and on which piers the Work 'to be heated supported and moved from one end of the heating chamber to the other, pas! .sages in the piers through which the hot gases maypass ici-oni channel 'to channel whereby to heat the under part of said work, means for drawing ott the products of coin biistion at the t'ar'end of the heating' chamber, and means covering' over the side channel adjacent the side doors to prevent the iipvard flow of gases from said channel.

3. ln a 'furnace for heatingr lslabs and the like. the combination ot means i'or entering burning gases into the heating chamber from a side thereof, a pair of tracks raised above the door ol the heating chamber and extending'lengthwise thereof in spaced relation to each other and to the sides ot the heating chaiiiher whereby open-top central and side channels are formed, means cover# inter over the side channels i'roin a point 1interniediate the length of the heating* chamber and one end thereof, doors opening into the heatingv chamber above and alongside a vby Way of the said channels, the coreredover channel in front ot the said doors preventing ythe hot gases from passing out through the doors .from below the Work' when thedoors are opened.

4. In a continuous heating fur-nace having aA combustion chamber at one side ot the heating chamber7 the combination of two ele- -iva'ted piers extending longitudinaily ot' the heating chamber i-n spaced relation to each other and lto the side walls et thefsame to form channels Aand on which piers the werk to be heated is supported and moved trom one end ot the heating chamber to the'other, -the hot gases troni the combustion chamber passing over and under the ends of the work into the side channels, transversely extending passages in the piersI through which the hot gases pass from the side channels into the *central channel, discharge ports in the loor of the heating chamber at the -tar end thereof through which the products ot combustion may pass out ot the chamber, and means for regulating the etfective size ot' the discharge ports.

5. In a continuous heating furnace haring a combustion chamber at one side ot the heating chamber and having doors along a side Wall of the latter, the combination of `two elevated piers extending longitudinally of the heating chamber in spaced relation to each other and to the side walls of the saine to form open-top channel and on which piers the work to be heated is supported and progressed from one end of the heating chamber to the other, the hot gases from the, combustion chamber passing over and under the ends of, the Work into the side channcls,lflateral ports in the piers through which the burning gases coming from the combustion chamber may pass from chan- I nel to channel whereby to heat the underside of said work, discharge ports in the floor ot' the heating chamber and at the tar end thereof for drawing ell' the productsot combustion, and means intcrcepting theI flow of bilrning gases in the side channel in front of said doors.

6. The combination specitiedin claim 2, and means in front ot the first side door and the adjacent side channel intercepting the free flow of hot gases in said'channel, the'adjacent pier having a passage through which hot gases may tloiv to the closedoverportion of the side channel.

7. In a pair or slab heating furnace, the combination oit' a heating chamber, means for admitting air and combustible lgas to the chamber at one side thereot` adjacent the lcharging end of the same, a pair of slabteuding through the piers on either side of the stop'walls whereby in front ot said walls the hbt gases may flow Jfrom the side channels into the central channel aiidon the other side of said walls from the central channel into the closcd-oif'er conduits, side doors in one side wall ot the heating chamber along and above the adjacent closed-over conduit, ports in the tloor of the heating chamber at the rear ends ot the channels through which the products of combustion 'may pass out of the heating chamber, means for controlling the llow of the products of Acombustion from the heating chamber, and

means Jor controlling the amount of air flowing into the combustion chamber.

.8. A -furnace having a heating chamber, a combustion chamber communicating with the heating chamber, a partition wall rising from the floor ot' the heating chamber and behind which wall the combustible gases from the producer How upwardly to the combustion chamber, ports extending upwardly through the wall and through which heated air flows into the combustion chamber from a source of supply, and a passage intermediate between the top. and bottom of said ports into which the air is received before vpassing into the combustion chamber.

9. In a fui-nace having a heating chamber wherein slabs aud the like may be heated,

. doors in one side wall of the heating chamber through which the heated slabs may be removed troni the latter, means Jfor entering air and gas into the chamber through the same side wall, products-ot-combustion outlet ports in the floorof said chamber beyond that side door which is most remote from the place where the air and gas are entered into the chamber, a rcouperator below the chamber floor, the inlet to the reciu'ierator facing on a pas ige which extends downwardly from said outlet p'oi'ts whereby the products of combustion may enter the reciiperator immediately on passing through. said ports, means for supplying fresh air to the reeuperator, an air-collecting chamber between said chamber floor and the top o't the recuperator iu which the air heated by the recupcrator collects, passages connecting the air chamber with the means for entering the air into the heating chamber.

10. In a heating Aobjects to be disposed therein cross-Wise of thedirection of travel of the objects through the furnace, the method of heating said objects which comprises initially circulating hot gases lengthwise 'of the 'Objects both above and beneath the same for a portion of their travel and thereafter to permitting the hot gases to flow in the direction of travel of the objects.

11. In a heating furnace adapted to permit objects to be disposed therein cross-Wise of the direction of travel vof the objects through the furnace, ,the 'method of heating said objects which emit-prises initially circulating hot gases lengthwise of the objects both above andbeneath the same for a portionA of their travel, and' for the remaining portion of their travel causing the gases' be- .loW the objects to divide into a plurality of independent streams for flow in the direction of travel of the objects.

In testimony whereof I aix my signature.

FORREST WILLIAM MANKER. 

